JP2008192222A - Magnetic sensing element and manufacturing method thereof - Google Patents

Abstract

Etch damage at the end of a magnetoresistive sensor 112 in ion beam etching is reduced.
In one embodiment of the present invention, ion beam etching (IBE) is used in a track width forming step (S12) of a magnetoresistive sensor 112. In this IBE, an Ar ion beam is incident on the substrate 51 in a state where the substrate 51 is tilted, and further, the substrate 51 is rotated about its normal direction as a rotation axis. In the conventional track width forming process, the IBE always irradiates the substrate 51 with an Ar ion beam while rotating the substrate 51. This IBE applies the Ar ion beam only in a predetermined angle range. The substrate 51 is irradiated.
[Selection] Figure 4

Description

  The present invention relates to a magnetic detection element and a manufacturing method thereof, and more particularly to a magnetic detection element in which a sense current flows in a stacking direction of a magnetoresistive sensor multilayer film and a manufacturing method thereof.

  A hard disk drive (HDD) includes a magnetic recording medium and a magnetic head, and data on the magnetic recording medium is read and written by the magnetic head. A magnetic head in the HDD includes a recording head that records information as a magnetization signal on a magnetic recording medium (magnetic disk), and a reproducing head that reads a signal recorded as a magnetization signal on the magnetic recording medium. The reproducing head is composed of a magnetoresistive layered body composed of a plurality of magnetic thin films and a nonmagnetic thin film, and reads a signal using the magnetoresistive effect, so that it is called a magnetoresistive head.

  There are several types of laminated structures of magnetoresistive effect heads, and they are classified into AMR heads, GMR heads, CPP-GMR heads, TMR heads and the like based on the principles of magnetoresistance used. AMR (magnetoresistance effect), GMR (giant magnetoresistance effect), CPP-GMR effect (Current Perpendicular Plane GMR effect), and TMR (tunnel magnetoresistance effect) are used to enter the read head from the magnetic recording medium, respectively. The input magnetic field is extracted as a voltage change.

  Currently, with the progress of higher sensitivity, a more sensitive reproduction method is required. In the range of 70 to 150 (Gb / in2), TMR having a very high MR ratio is advantageous in terms of improving sensitivity. Then, it is considered that CPP-GMR or the like becomes mainstream for an ultrahigh recording density exceeding 150 (Gb / in2). About TMR, it is disclosed by patent document 1, for example. CPP-GMR is disclosed in, for example, Patent Document 2. TMR and CPP-GMR are different from CIP-GMR (Current In Plane GMR) in which a sense current flows in parallel to the film surface of the magnetoresistive effect laminated body, in a direction perpendicular to the film surface, that is, in the stacking direction of the film surface. This is a method of flowing a sense current. In this specification, such a method is called a CPP method. Such a reproducing head is called a CPP type reproducing head.

  FIG. 17A is a cross-sectional view schematically showing the configuration of the CPP type reproducing head 71. The magnetoresistive sensor 712 is between the lower shield 711 and the upper shield 713. The lower shield 711 and the upper shield 713 function as a magnetic shield and also serve as a lower electrode and an upper electrode that supply a sense current to the magnetoresistive sensor 712. An upper magnetic isolation film 714 made of a conductor is formed below the upper shield 713.

  The magnetoresistive sensor 712 includes a sensor base layer 271, an antiferromagnetic film 272, a fixed layer 273, a nonmagnetic intermediate layer 274, a free layer 275, and a sensor cap film 276, which are sequentially stacked from the lower layer side. An exchange interaction with the antiferromagnetic film 272 acts on the fixed layer 273 and its magnetization direction is fixed. When the reproducing head 71 is a TMR head, the nonmagnetic intermediate layer 274 is formed of an insulator such as alumina (AL2O3) or magnesium oxide (MgO), and when using CPP-GMR, the nonmagnetic intermediate layer 274 is a Cu alloy. It is formed using a nonmagnetic conductor such as. The track width of the free layer 275 is indicated by Twf.

  When the relative magnetization direction of the free layer 275 with respect to the magnetization direction of the fixed layer 273 changes due to the magnetic field from the magnetic disk, the resistance value (current value) of the magnetoresistive sensor 712 changes. Thus, the reproducing head 71 can detect an external magnetic field. Hard bias films 715 exist on the left and right sides of the magnetoresistive sensor 712. The bias magnetic field from the hard bias film 715 works to make the free layer 275 a single magnetic domain. The hard bias film 715 is formed on the hard bias base film 716. A junction insulating film 717 is formed as a lower layer of the hard bias base film 716. The insulating film 717 exists between the hard bias base film 716, the lower shield film 711 and the magnetoresistive sensor 712, and prevents the sense current from flowing outside the magnetoresistive sensor 712.

Next, the manufacturing process of the CPP reproducing head 71 will be described. First, a multilayer film constituting the magnetoresistive sensor 712 is deposited by sputtering. Thereafter, a resist is formed by resist application and patterning, and the track width of the multilayer magnetoresistive sensor 712 is formed by etching using ion milling. After that, an insulating film 717 is formed. Further, a hard bias base film 716 and a hard bias film 715 are formed. Thereafter, the resist is lifted off, and an upper magnetic isolation film 714 and an upper shield film 713 are formed.
Japanese Patent Laid-Open No. 3-154217 Japanese National Patent Publication No. 11-509956

  In the etching process of the magnetoresistive sensor 712, the side end portion of the magnetoresistive sensor 712 is exposed to etching particles. At this time, as shown in FIG. 17B, an etching damage layer 781 is formed on the exposed surface. It has been found that the etching / damage layer 781 formed at the end of the magnetoresistive sensor 712 in this etching process deteriorates the characteristics and reliability of the magnetoresistive sensor 712. Specifically, it has been found that the shunt current flowing through the etching damage layer 781 is a big problem. Therefore, it is required to suppress etching damage in the etching process of the magnetoresistive sensor 712.

  Alternatively, in the CPP reproducing head 71, the dielectric strength characteristics of the insulating film 717 are important, and at the same time, the thickness and shape of each layer near the end of the magnetoresistive sensor 712 are important. For example, the hard bias film 715 having a conventional structure shown in FIG. 17A is formed thick in the vicinity of the side end of the magnetoresistive sensor 712, and the film thickness gradually increases from the vicinity of the end of the magnetoresistive sensor 712. ing. Therefore, a large step USh is formed in the upper shield 713 near the side end of the magnetoresistive sensor 712, and the upper shield 713 has a deep concave shape on the magnetoresistive sensor 712.

  Thereby, on the magnetoresistive sensor 712, the upper shield 713 is not flattened or the flattened width is reduced. As described above, if the upper shield 713 is not sufficiently flattened with respect to the free layer track width Twf, the effect of the upper shield 113 is reduced at the end of the magnetoresistive sensor 112, and there is a problem that the reading blur width is increased. In particular, this problem becomes significant in a reproducing head having a small shield interval Gs.

  One aspect of the present invention is a magnetoresistive sensor having a fixed layer whose magnetization direction is fixed, a free layer whose magnetization direction is changed by an external magnetic field, and a nonmagnetic intermediate layer between the fixed layer and the free layer. The magnetic sensing element includes a multilayer film, and a current flows in a direction perpendicular to the film surface of the magnetoresistive sensor multilayer film. This element is formed on upper and lower shield electrodes formed so as to sandwich the magnetoresistive sensor multilayer film in the vertical direction, and on both ends of the magnetoresistive sensor multilayer film, and applies a bias magnetic field to the free layer. A magnetic domain control film to be added; a sensor multilayer film lower layer formed below the fixed layer, the free layer, and the nonmagnetic intermediate layer; and having a step that decreases in thickness as it moves away from the magnetoresistive sensor multilayer film; An insulating film having a step formed in contact with both end portions of the magnetoresistive sensor multilayer film and having a thickness formed thin on the magnetoresistive sensor multilayer film side according to the step of the lower layer. With the structure of the insulating film, it is possible to adjust the shape of each layer in the vicinity of the sensor and to realize a reproducing head with excellent withstand voltage reliability.

  It is preferable that end angles of the fixed layer, the free layer, and the nonmagnetic intermediate layer are 45 ° or more. Thereby, a bias magnetic field can be effectively applied to the free layer. Alternatively, in the region overlapping the magnetoresistive sensor multilayer film, the upper shield electrode is substantially flat, and the substantially flat region includes the track width of the free layer, the upper shield electrode, and the lower shield electrode. It is preferable that it is more than the sum with the value of 2 times the space | interval between. As a result, the lead characteristics can be improved.

  The fixed layer, the nonmagnetic intermediate layer, and the free layer are sequentially stacked from the bottom to the top, and the magnetic domain control film has a step formed with a thin thickness on the magnetoresistive sensor multilayer film side. In the vicinity of the side edge of the magnetoresistive sensor multilayer film, the height position of the upper end surface of the magnetic domain control film is preferably 5 nm or less from the height of the upper end face of the magnetoresistive sensor multilayer film. As a result, a bias magnetic field can be effectively applied to the free layer, and the magnetic stability of the hard bias film can be increased.

  The magnetic domain control film has a step formed with a thin thickness on the magnetoresistive sensor multilayer film side, and the thickness on the magnetoresistive sensor multilayer film side in the step of the magnetic domain control film has an anti-magnetic resistance sensor multilayer film The thickness of the side can be ½.

  According to another aspect of the present invention, there is provided a magnetoresistive device comprising: a fixed layer having a fixed magnetization direction; a free layer whose magnetization direction is changed by an external magnetic field; and a nonmagnetic intermediate layer between the fixed layer and the free layer. This is a method of manufacturing a magnetic detection element that includes a sensor multilayer film and in which a current flows in a direction perpendicular to the film surface of the magnetoresistive sensor multilayer film. In this method, a multilayer film is formed on a substrate, a patterned photoresist is attached on the multilayer film, and etching particles are applied to the multilayer film at an angle inclined with respect to the substrate in a state where the photoresist is attached. The magnetoresistive sensor multilayer film is etched to form a side end shape of the magnetoresistive sensor multilayer film, and the etching has an incident angle in a limited incident angle range set in advance with respect to the photoresist. The light is incident on the multilayer film while being changed. As a result, etching damage to the magnetoresistive sensor can be reduced, and effective shape control can be performed.

  Preferably, in the etching, the etching particles are incident on the multilayer film at a timing corresponding to the preset limited incident angle range while rotating the substrate on the tilt angle. Thereby, processing can be performed easily and effectively.

  Preferably, after forming the shape of the side end portion of the magnetoresistive sensor multilayer film, the insulating film on the side end portion side of the magnetoresistive sensor multilayer film, and the magnetic domain control film on the side of the antimagnetic resistance sensor multilayer film of the insulating film And each of the insulating film and the magnetic domain control film is formed at a slant angle with respect to the substrate, and a predetermined incident angle set in advance with respect to the photoresist. The material particles are incident while changing the incident angle in the range. Thereby, effective shape control in film formation becomes possible. Further, each of the formation of the insulating film and the magnetic domain control film is performed by rotating the substrate on the tilt angle while supplying the material particles to the substrate at a timing corresponding to the preset limited incident angle range. Incident light is preferable. Alternatively, it is preferable that the tilt angle and the incident angle range in the formation of the insulating film are set so that the upper surface of the insulating film is flattened based on the tilt angle and the incident angle range in the etching.

  According to the present invention, it is possible to suppress degradation of element characteristics in a magnetoresistive detection element having a magnetoresistive sensor multilayer film in which a sense current flows in the stacking direction.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same element, and duplication description is abbreviate | omitted as needed for clarification of description. In the embodiment described below, the present invention is applied to a reproducing head of a hard disk drive (HDD) which is an example of a magnetic detection element. The reproducing head of this embodiment is a CPP (Current Perpendicular Plane) type head in which a sense current flows in the stacking direction of the magnetoresistive sensor multilayer film (direction perpendicular to the film surface).

  Before describing the features of this embodiment, the overall configuration of the magnetic head will be described first. FIG. 1 is a cross-sectional view schematically showing the structure of the magnetic head 1. The magnetic head 1 reads and writes magnetic data from and to the magnetic disk 3. In FIG. 1, the magnetic disk 2 rotates in the right direction, and the traveling direction of the magnetic head 11 is the left direction in FIG. The magnetic head 1 has a reproducing head 11 and a recording head 12 from the running direction side (leading side). The magnetic head 1 is formed on the trailing side of the slider 2 (the side opposite to the leading side). The magnetic head 1 and the slider 2 constitute a head slider. The reproducing head 11 has a lower shield 111, a magnetoresistive sensor 112, and an upper shield 113 from the leading side. The recording head 12 has a thin film coil 121 and a recording magnetic pole 122. The thin film coil 121 is surrounded by an insulator 123.

  The recording head 12 is an inductive element that generates a magnetic field between the recording magnetic poles 122 by a current flowing through the thin film coil 121 and records magnetic data on the magnetic disk 11. The reproducing head 11 is a magnetoresistive element and includes a magnetoresistive sensor 112 having magnetic anisotropy. The reproducing head 11 receives magnetic data recorded on the magnetic disk 2 according to the resistance value that changes according to the magnetic field from the magnetic disk 2. read out. The reproducing head of this embodiment is a CPP type reproducing head, and the lower shield 111 and the upper shield 113 are used as electrodes for supplying a detection current to the magnetoresistive sensor 112.

  The magnetic head 1 is formed on an AlTiC (AlTiC) substrate constituting the slider 3 by using a thin film forming process. The magnetic head 1 and the slider 3 constitute a head slider. The head slider floats on the magnetic disk 3, and the magnetic disk facing surface 21 is called ABS (Air Bearing Surface). The magnetic head 1 includes a protective film 13 such as alumina around the recording head 12 and the reproducing head 11, and the entire magnetic head 1 is protected by the protective film 13.

  FIG. 2 is a cross-sectional view schematically showing the configuration of the read head 11 of this embodiment, which is an example of a magnetoresistive detection element. FIG. 2 schematically shows a cross-sectional structure viewed from the ABS surface 21 of the head slider, that is, the air bearing surface facing the magnetic disk 3. The lower side in FIG. 2 is the leading side, and the upper side is the trailing side. In this specification, the AlTiC substrate side on which the reproducing head 11 is formed, that is, the slider 2 side is defined as the lower side, and the trailing side, which is the opposite side, is defined as the upper side. Each layer of the reproducing head 11 is sequentially formed from the lower side. The reproducing head 11 of this embodiment is a CPP reproducing head such as a TMR (Tunneling Magneto Resistance) head or a CPP-MR (Magneto Resistance) head, and the sense current flows in the vertical direction in FIG.

  The magnetoresistive sensor 112 is between the lower shield 111 and the upper shield 113. A distance between the upper surface of the lower shield 111 and the lower surface of the upper shield 113 is shown as a shield interval Gs. The lower shield 111 and the upper shield 113 are made of a conductive magnetic material, function as a magnetic shield, and also serve as a lower electrode and an upper electrode that supply a sense current to the magnetoresistive sensor 112. The lower shield 111 and the upper shield 113 are made of, for example, an alloy containing Ni, Fe, Co, or the like. An upper magnetic isolation film 114 made of a conductor is formed below the upper shield 113.

  The magnetoresistive sensor 112 is a laminated body composed of a plurality of layers. The magnetoresistive sensor 112 includes a sensor base layer 211, an antiferromagnetic film 212, a fixed layer 213, a nonmagnetic intermediate layer 214, a free layer 215, and a sensor cap film 216, which are sequentially stacked from the lower layer side. . Each layer is in physical contact with an adjacent layer.

  The sensor underlayer 211 is formed of a nonmagnetic material such as Ta or NiFeCo alloy, and may be formed of a single layer as shown in the figure, or may have a laminated structure. The antiferromagnetic film 212 is formed of an antiferromagnetic material such as PtMn. The fixed layer 213 in FIG. 2 is a laminated fixed layer, and is composed of a two-layered ferromagnetic film made of a CoFe alloy or the like and a nonmagnetic layer made of Ru or the like therebetween. The two layers of ferromagnetic films are coupled by exchange interaction, and the magnetization is stabilized. An exchange interaction with the antiferromagnetic film 212 acts on the lower ferromagnetic film, and its magnetization direction is fixed. Note that the fixed layer 213 may have a single-layer structure.

  When the reproducing head 11 is a TMR head, the nonmagnetic intermediate layer 214 is formed of an insulator such as magnesium oxide (MgO) and functions as a tunnel barrier. On the other hand, when the reproducing head 11 uses CPP-GMR, the nonmagnetic intermediate layer 214 is formed using a nonmagnetic conductor such as Cu. The free layer 215 is formed of a metal magnetic material such as a NiFe alloy or a CoFe alloy. The free layer 215 can also be a single layer or a laminated structure. The track width of the free layer 215 is indicated by Twf. The sensor cap film 216 is made of a nonmagnetic conductive material such as Ta.

  When the relative magnetization direction of the free layer 215 with respect to the magnetization direction of the fixed layer 213 is changed by the magnetic field from the magnetic disk 3, the resistance value (current value) of the magnetoresistive sensor 112 changes. Thus, the reproducing head 11 can detect an external magnetic field. In order to suppress Barkhausen noise and the like due to magnetic domain non-uniformity of the free layer 215, hard bias films 115, which are magnetic domain control films, exist on both the left and right sides of the magnetoresistive sensor 112. The bias magnetic field from the hard bias film 115 controls the magnetic domain of the free layer 215 and functions to make the free layer 215 a single magnetic domain. The hard bias film 115 is formed on and in contact with the hard bias base film 116. A hard bias protective film 117 is formed on the hard bias film 115.

The reproducing head 11 has a junction insulating film 16 between the magnetoresistive sensor 112 and the hard bias film 115 on both the left and right sides in the track width direction (left and right direction in FIG. 2) of the magnetoresistive sensor 112. The junction insulating film 16 can be formed of, for example, Al ₂ O ₃ . The junction insulating film 16 insulates between the upper shield film 113 and the lower seal film 111 outside the magnetoresistive sensor 112 and blocks a sense current outside the magnetoresistive sensor 112.

  The hard bias film 115 is made of a CoCrPt alloy, a CoPt alloy, or the like, and is conductive. The hard bias base film 116 is also a conductor made of Cr or the like. Therefore, the junction insulating film 167 prevents the sense current from flowing between the upper shield film 113 and the lower seal film 111 via the hard bias film 115 without passing through the nonmagnetic intermediate layer 214, and the necessary magnetic field. The output of the resistance sensor 112 is achieved.

  The magnetoresistive sensor 112 according to the present embodiment has a step on the lower layer side that decreases in thickness as the distance from the multilayered magnetoresistive sensor film increases. As shown in FIG. 2, the lower layer below the fixed layer 213, specifically, the antiferromagnetic layer 212 and a part of the sensor base layer 211 therebelow are left without being etched. These lower layers extend to both outer sides in the track width direction from the side edges of the fixed layer 213, the nonmagnetic intermediate layer 214, and the free layer 215, and their width Lsw is equal to the fixed layer 213, the nonmagnetic intermediate layer. Larger than layer 214 and free layer 215. That is, the antiferromagnetic layer 212 and the sensor base layer 211 below the antiferromagnetic layer 212 adjacent to the fixed layer 213 are located on the left and right sides of the side edges of the fixed layer 213, the nonmagnetic intermediate layer 214, and the free layer 215. It extends on both sides. The distance between the step and the end of the magnetoresistive sensor 112 is about 0.05 to 0.2 μm.

  The antiferromagnetic layer 212 is partially etched on the outer side, and the outer thickness is thinner than the thickness of the region overlapping the fixed layer 213. The antiferromagnetic layer 212 gradually decreases in thickness as it moves away from the side end of the magnetoresistive sensor 112 (coincides with the side end of the free layer 215, etc.), and then gradually after a substantially flat region continues. Have an end where the thickness decreases. The end of the sensor underlayer 211 coincides with the end of the antiferromagnetic layer 212 at the position in the track width direction.

  The junction insulating film 16 has a thickness (size in the vertical direction) corresponding to the steps of the antiferromagnetic layer 212 and the sensor underlayer 211. Specifically, the thickness on the antiferromagnetic layer 212 is thinner than the portion outside the side end of the antiferromagnetic layer 212. For example, the junction insulating film 167 is formed in contact with the lower seal film 111 outside the antiferromagnetic layer 212 with respect to the thickness of the portion in the vicinity of the magnetoresistive sensor 112 that is substantially constant. Can be doubled in thickness. As described above, the junction insulating film 16 corresponding to the width Lsw can be thinned in the vicinity of the magnetoresistive sensor 112, and the film thickness can be increased with a certain width on the outside thereof. In addition, it is possible to realize a reproducing head having excellent withstand voltage reliability.

  Further, the lower surface of the junction insulating film 16 has a shape corresponding to the shapes of the antiferromagnetic layer 212 and the sensor underlayer 211. Specifically, the lower surface of the junction insulating film 16 has a step Lsh corresponding to the steps of the antiferromagnetic layer 212 and the sensor base layer 211. For this reason, the upper surface of the junction insulating film 16 is substantially flat. By flattening the upper surface of the junction insulating film 167, the hard bias base film 116 deposited thereon can be more uniformly deposited, and the lower surface of the hard bias film 115 can be uniformized. This can contribute to improving the characteristics of the hard bias film 115.

  The hard bias film 115 of this embodiment has two steps in the track width direction, and a step is formed on the upper surface thereof. Specifically, the hard bias film 115 is thinned in the vicinity of the magnetoresistive sensor 112, and the outer thickness of the magnetoresistive sensor 112 is formed thick. The hard bias film 115 gradually decreases in thickness as it moves away from the end on the magnetoresistive sensor 112 side, and a thinned region having a substantially constant thickness is formed in the vicinity thereof. Further, a step portion where the film thickness gradually increases is formed on the outer side, and thereafter, a thickened region having a substantially constant film thickness is formed with a predetermined width (horizontal dimension in the drawing). For example, the thickness of the outer thick film portion can be doubled with respect to the film thickness of the flat portion near the magnetoresistive sensor 112.

  By thinning the hard bias film 115 in the vicinity of the magnetoresistive sensor 112, the bias magnetic field to the free layer 215 can be controlled more effectively. By aligning the height position of the thin hard bias film 115 with the free layer 215, the bias magnetic field applied to the free layer 215 can be localized and optimized. In addition, by forming a thickened portion outside the thinned portion of the magnetoresistive sensor 112, magnetic instability of the hard bias film 115 due to thinning in the vicinity of the magnetoresistive sensor 112 can be eliminated. That is, by increasing the thickness of the free layer 215, the magnetic stability can be increased, and the magnetic stability of the thin hard bias film 115 layer near the magnetoresistive sensor 112 can be improved by the magnetic field from that portion.

  Here, the upper surface height position of the hard bias film 115 in the vicinity of the magnetoresistive sensor 112 is preferably substantially coincident with the upper surface height position of the free layer 215, or the upper surface height position of the free layer 215 is higher. It is preferable to be below the position of 5 nm (see Fsh in FIG. 2). As a result, the bias magnetic field leaking from the hard bias film 115 to the upper shield 113 can be reduced when the hard bias film 115 approaches the upper shield 113 in the vicinity of the magnetoresistive sensor 112. As a result, a decrease in the bias magnetic field applied to the free layer 215 can be suppressed.

  The thinning of the junction insulating film 16 and the hard bias film 115 in the vicinity of the magnetoresistive sensor 112 contributes to the flattening of the upper shield 113. In particular, the above structure is effective for flattening the upper shield 113 when the shield interval Gs is reduced to increase the recording frequency of the magnetic disk. When the upper shield 113 has a concave shape on the upper side of the magnetoresistive sensor 112 (see the prior art in FIG. 17A), the effect of the upper shield 113 is reduced at the end of the magnetoresistive sensor 112 and the reading blur width is increased. Resulting in. Therefore, it is preferable to flatten the upper shield 113 over the free layer track width Tfw. In the reproducing head 11 of FIG. 2, the upper shield 113 is substantially flat.

  In the reproducing head 11 of FIG. 2, the junction insulating film 167 and the hard bias film 115 are thinned on the antiferromagnetic layer 212. As a result, the upper surface of the thin hard bias film 115 in the vicinity of the magnetoresistive sensor 112 is located below the upper surface of the sensor cap film 216. The upper shield 113 is planarized corresponding to the thinned and planarized region, and as a result, has a planarization width of Usw. The upper shield flattening width Usw is larger than the free layer track width Tfw and has a sufficient size, and is preferably configured to be approximately equal to or larger than the size of the free layer track width Tfw + 2Gs. As a result, the output characteristics can be maximized while suppressing the reading bleeding at the end of the free layer 215.

  Here, in order to flatten the upper surface of the upper shield 113 at a position overlapping the free layer 215, it is important that the thickness of the hard bias film 115 is not too large. In the structure of FIG. 2, the upper surface height position of the film thickness portion outside the hard bias film 115 is equal to or lower than the lower surface height position at the position overlapping the free layer 215 of the upper shield 113. By adopting this structure, the step Ush of the upper shield 113 can be reduced, and the flattening of the shape of the upper shield 113 on the upper side of the free layer 215 can be further improved. The size of the step Ush is preferably 20 nm or less, and more preferably 10 nm or less.

  Next, the manufacturing process of the reproducing head structure shown in FIG. 2 will be described with reference to the flowchart of FIG. First, a multilayer film constituting the magnetoresistive sensor 112 is deposited by sputtering (S11). Thereafter, a resist layer is formed by resist application and patterning (S12). The track width of the magnetoresistive sensor 112 is formed by etching using ion beam etching (ion milling) (S13). This embodiment is characterized by this etching process, which will be described later. By this etching, the sensor cap film 216 to the sensor underlayer 211 are etched.

  Thereafter, a junction insulating film 167 is attached (S14). Further, a hard bias film 115 is attached (S15). In this embodiment, the junction insulating film 167 and the hard bias film 115 are formed by ion beam deposition (IBD). This embodiment is also characterized by the method of attaching these layers, which will be described later. Thereafter, after forming the hard bias film protection 117 (S16), the resist is peeled off by lift-off (S17).

  Hereinafter, the track width forming step (S13) of the magnetoresistive sensor 112 in this embodiment will be described in detail. FIG. 4 is an overview of ion beam etching (IBE) used in the magnetoresistive sensor 112 track width forming step (S13) in this embodiment. The rectangles on the substrate 51 indicate resists 52 that are patterned corresponding to the reproducing head elements. In this IBE, an Ar ion beam is incident on the substrate in a state where the substrate is tilted, and the substrate 51 is rotated with its normal direction as a rotation axis. In the conventional track width forming process, the IBE always irradiates the substrate 51 with an Ar ion beam while rotating the substrate 51. However, in this type of IBE, only within a predetermined substrate rotation angle range set in advance. The substrate 51 is irradiated with an Ar ion beam.

  In the example of FIG. 4A, the incident angle of the Ar ion beam is inclined with respect to the normal direction of the substrate 51, and the inclination angle is α. The substrate 51 is uniformly rotated at a substantially constant angular velocity about the normal direction. As a characteristic point of this IBE, while the substrate 51 is rotating, the Ar ion beam does not always enter the substrate 51 but intermittently. FIG. 4B schematically shows this state. Specifically, the substrate is rotated at an inclination angle α. The resist is formed in a vertical contrast direction. An Ar ion beam is generated and incident on the substrate only when the angle in the substrate rotation direction is a rotation angle of β around γ.

  The incident angle of the Ar ion beam with respect to the normal direction of the substrate is constant. However, for the incident direction of the projected Ar ion beam with respect to the rotation direction of the substrate surface, the incident direction is limited to a certain selected angle range with respect to the resist 52 (the magnetoresistive sensor 121). . Accordingly, the incident angle can be controlled with respect to the slope of the side end portion of the Ar ion beam magnetoresistive sensor 112, and the etching shape of the slope at the side end portion of the magnetoresistive sensor 112 is controlled with high accuracy. Will be able to. Alternatively, by appropriately selecting the incident angle of a part of the Ar ion beam, it is possible to reduce etching damage while minimizing redeposition to the inclined surface at the side end of the magnetoresistive sensor 112.

  FIG. 5A schematically shows a relative change in the incident direction of the Ar ion beam with respect to the substrate 51. FIG. 5B schematically shows the incident direction of the Ar ion beam with respect to the side end face of the magnetoresistive sensor 112. While the substrate 51 is rotating, the incident angle α of the Ar ion beam with respect to the normal direction of the substrate 51 is constant. Therefore, as shown in FIG. 5A, the incident direction of the Ar ion beam including the state where it is not actually incident is relatively old as viewed from the substrate 51 and centered on the normal direction of the substrate 51. Perform differential exercise. When the incident direction is projected onto the substrate surface, the incident angle range in the in-plane direction is limited to a specific range.

  In this IBE, as shown in FIG. 5A, Ar ion particles, which are etching particles, are incident in a selected angle range having an incident direction that rotates within the projected substrate surface. It is important to select a symmetric angle range in the vertical and horizontal directions in FIG. 4B and perform etching in the vicinity of the photoresist 52 symmetrically.

  FIG. 4B and FIG. 5A show an example of two-fold symmetry. The angle range of each incidence is symmetric in the vertical and horizontal directions in FIG. That is, the Ar ion beam is incident four times intermittently around the photoresist 52 (the magnetoresistive sensor 112). The sweep angle β at each incidence is the same (incident angle range where incident is continuously performed), and the angle γ between each incident central angle (incident direction at the center during the sweep) and the track width direction is the same. is there. That is, Ar ion beam incidence is skipped in a specific angle range centered on the track width direction and a specific angle range centered on a direction perpendicular to the track width direction.

  There are several methods for limiting the incident angle range of the Ar ion beam. For example, 1) Etching is performed while controlling the rotation direction of the substrate and reciprocatingly oscillating, or 2) Opening / closing the shutter when the substrate rotation angle reaches the required incident angle, or 3) The substrate at the required incident angle. The incident timing of the Ar ion beam can be controlled, for example, by slowing the rotation speed when the rotation angle comes so as to effectively etch only at a certain incident angle.

  However, as described above, it is more rational and preferable to control the incident angle control of the Ar ion beam in the substrate rotation direction than to control it mechanically. Also, the problem of redeposition may remain when trying to control mechanically. That is, while the substrate is tilted and rotated, an ion beam is generated from the ion gun only when the substrate is within the required angle range of the particle incident direction, and etching is performed by a pulsed ion beam synchronized with the rotation of the substrate. Is preferred. The ion beam incidence timing can be easily controlled by electrically controlling the acceleration voltage of the ion gun.

  FIG. 6A illustrates the change in acceleration voltage corresponding to the example of FIGS. 4B and 5A. In this example, four intermittent Ar ion beams are incident, so the acceleration voltage shows four pulses with respect to the angle of the horizontal axis. The angle indicates the angle of the substrate 51, that is, the angle of the incident direction of the Ar ion beam projected onto the substrate 51, and 0 ° is the direction along the side end face of the magnetoresistive sensor 112, that is, in FIG. The vertical direction is a direction perpendicular to the ABS surface.

  Each pulse waveform is symmetric about 180 °. Also, the two pulse waveforms between 0 ° and 180 ° are symmetrical around 90 °, and the two pulse waveforms between 180 ° and 360 ° (0 °) are around 270 °. It is symmetrical. 90 ° and 270 ° correspond to the track width direction when the incident direction of the Ar ion beam is projected onto the substrate 51. FIG. 6B shows an example of an acceleration voltage waveform corresponding to a single Ar ion beam incidence. The rising and falling slopes are in a condition range in which the Ar ion beam can be stably generated. Set the optimum value by design.

  FIG. 7A shows the state of etching (S12) of the magnetoresistive sensor 112 covered with the photoresist 52. The state after the track width forming step (S12) by etching as viewed from the ABS side is shown. Show. The magnetoresistive sensor 112 is covered with a patterned photoresist 52, and a portion exposed from the photoresist 52 is etched by an Ar ion beam. FIG. 7A shows the range of the incident direction in which the Ar ion beam changes.

  As described above, the Ar ion beam is incident symmetrically with respect to the substrate surface vertically and horizontally. FIG. 7B shows a change in the Ar ion beam incident direction and the corresponding acceleration voltage when viewed from the top surface of the substrate. Specifically, FIG. 7B shows the incident direction of the two-fold symmetric Ar ion beam and the acceleration voltage waveform corresponding to the incident direction.

  In FIG. 7B, the 12 o'clock direction of the circle indicating the incident direction corresponds to 0 ° in the waveform graph. The incident direction changes, for example, clockwise, and the angle of the waveform diagram with respect to each direction increases accordingly. In the 2-fold symmetry, Ar ion beam irradiation is performed twice on each of the left and right sides of the magnetoresistive sensor 112 in the track width direction.

  As shown in FIG. 7 (a), when the Ar ion beam is incident from the right side of the magnetoresistive sensor 112, the entire area on the right side of the magnetoresistive sensor 112 is exposed to the Ar ion beam, but the one on the opposite left side is exposed. The portion becomes a shadow of the photoresist 52, and the Ar ion beam does not enter there. Similarly, when the Ar ion beam is incident from the left side of the magnetoresistive sensor 112, the entire left region of the magnetoresistive sensor 112 is exposed to the Ar ion beam, but a part of the right side becomes the shadow of the photoresist 52 and Ar The ion beam is not incident. Since the incident direction of the Ar ion beam is bilaterally symmetric, the region where the Ar ion beam is etched is also bilaterally symmetric.

  As the Ar ion beam incident direction approaches the vertical direction of FIG. 7B, that is, 0 ° and 180 °, the shadowed portion on the opposite side of the photoresist 52 becomes smaller. Therefore, in the angular range where the Ar ion beam is actually incident, the outer width (OUTER WIDTH) of the lower layer of the magnetoresistive sensor 112 at the angular position closest to the track width direction (90 ° and 270 °). ) Is decided.

  Further, the inner width (INNER WIDTH) of the lower layer of the magnetoresistive sensor 112 is determined at the angular position where the Ar ion beam incident direction is farthest from the track width direction (closest to 0 ° and 180 °). The film thicknesses of the antiferromagnetic layer 212 and the sensor underlayer 211 gradually change between the position defining the inner width and the position defining the outer width of the lower layer of the magnetoresistive sensor 112. As described above, the steps of the antiferromagnetic layer 212 and the sensor base film 211 are formed by limiting the incident direction of the Ar ion beam.

  Here, the change in the etching state with respect to the change in the Ar ion beam incident direction due to the rotation of the substrate 51 will be described. FIG. 8A schematically shows the incident angle of the Ar ion beam at the end of the magnetoresistive sensor 112. The Ar ion beam is incident with an inclination with respect to the normal direction of each surface. When the incident direction of the Ar ion beam with respect to the substrate 51 changes, the incident angle with respect to the surface of the end portion on the magnetoresistive sensor 112 side changes. Etching damage to each layer varies depending on the incident angle of the Ar ion beam.

  Compared to the case where an Ar ion beam is incident perpendicularly to the layer surface (incidence angle 0 °) as shown in FIG. 8B, it is inclined with respect to the layer surface as shown in FIG. (Corresponding to an increase in incident angle) The depth of etching damage can be reduced when the Ar ion beam is incident. In the etching process of the magnetoresistive sensor 112, it is important to reduce the etching damage at the side edges. This is because if the etching / damage layer is deep, a shunt current flows through the layer, and the magnetoresistive sensor 112 does not function normally. Therefore, it is particularly important to reduce etching damage at the end of the nonmagnetic intermediate layer 214 side.

  In the IBE, in forming the end shape of the magnetoresistive sensor 112, the incident angle of the Ar ion beam to the side end portion of the magnetoresistive sensor 112 is inclined with respect to the track width direction. Specifically, as shown in FIG. 4B, the incident direction of the Ar ion beam is limited to an incident angle in the angle range β with the inclination angle γ as the center with respect to the track width direction. Incidence in the track width direction has the smallest incident angle with respect to the normal direction of the side end surface, and the incident angle on the side end surface increases with distance from the direction. From the viewpoint of etching damage, it is preferable to increase the incident angle, that is, to increase β and decrease β.

  However, if the incident angle is increased too much, the etching rate is greatly reduced and the angle of the side end portion becomes smaller, that is, the inclination of the side end portion becomes gentle. FIG. 9 is a graph showing an example of the relationship between the incident angle of the Ar ion beam and the etching rate. O, □, and X are in order of increasing energy, and are graphs normalized by the etching rate when the incident angle is 0 degree. It can be seen that the etching rate decreases when the etching energy is low, and the etching rate varies depending on the incident angle.

  Accordingly, by selecting the optimum etching angle and conditions for the inclination angle of the side end portion of the magnetoresistive sensor 112, the ratio of the etching rate to the side end inclination angle and the etching rate in the normal direction of the substrate surface can be obtained. It becomes possible to select. As a result, the inclination angle of the side end can be improved while reducing etching damage.

  Therefore, from the viewpoint of the characteristics of the magnetoresistive sensor 112, it is preferable that the slope of the side end of the magnetoresistive sensor 112 is steep. Specifically, it is preferable that the inclination angle (see ψ in FIG. 2) of the side ends of the fixed layer 213, the nonmagnetic intermediate layer 214, and the free layer 215 is 45 ° or more. Here, the inclination angle corresponds to an angle with respect to the track width direction on the film surface of the magnetoresistive sensor 112. From the above, in the actual manufacturing process, the etching energy and the angle range of the incident direction of the ion beam are determined so that the end of the magnetoresistive sensor 112 side is steep and the etching damage is reduced. .

  Here, when the IBE in the magnetoresistive sensor 112 etching step (S13) is based only on the above method, it is conceivable that the processing time becomes long and the throughput decreases. Therefore, it is preferable to change the incident angle range of the Ar ion beam during the etching process at the end of the magnetoresistive sensor 112. As a result, the final etching damage can be reduced and the throughput can be increased. FIG. 10 shows a preferable example of a method for controlling the incident angle range of the Ar ion beam. In FIG. 10, the magnetoresistive sensor 112 etching step (S13) includes three steps: an initial shape forming step, an end shape forming step, and a damaged layer removing step.

  The circle in each step indicates rotation in the incident direction with respect to the substrate surface, and the radius increases as the inclination angle α with respect to the substrate normal increases. In the initial shape forming process, an Ar ion beam is incident from all directions according to the rotation of the substrate. In addition, the inclination angle α with respect to the substrate normal is set to be smaller than in the subsequent steps.

  Subsequently, the inclination angle α with respect to the substrate normal is increased to perform the edge shape forming step. In this step, the Ar ion beam is incident on the substrate only in a specific angle range in the direction of rotation with respect to the substrate surface. In contrast to the two-fold symmetry Ar ion beam incidence in the subsequent damage layer removal step, this step is one-time symmetry Ar ion beam incidence.

  That is, the Ar ion beam is incident in a specific angle range symmetric about the track width direction from the left and right directions in the track width direction (left and right direction in FIG. 10, 90 ° and 270 ° in FIG. 7B). To do. Then, Ar ion beam incidence is skipped in a predetermined angle range centering on a direction (vertical direction in FIG. 10, 0 ° and 180 ° in FIG. 7B) perpendicular to the track width direction on the substrate surface.

  In this step, the end shape of the magnetoresistive sensor 112 is determined. As described with reference to FIGS. 7A and 7B, the outer width (OUTER WIDTH) of the lower layer of the magnetoresistive sensor 112 is defined at the incidence in the track width direction, and is the angle farthest from the track width direction. The inner width (INNER WIDTH) is defined at the incidence at. In this process, since the Ar ion beam is incident within an angle range centering on the track width direction, the Ar ion beam incident angle to the end of the magnetoresistive sensor 112 is reduced, and the etching damage depth is increased. Become. However, the etching time per rotation of the substrate is long, and by including a specific incident angle, the etching rate can be increased and the processing time can be shortened. In this step, the removal of the redeposition film by etching is also performed.

  Subsequently, the damage layer removing step is performed by further increasing the inclination angle α with respect to the substrate normal. This process is a two-fold Ar ion beam incidence similar to the method described with reference to FIGS. 7 (a) and 7 (b). The damage layer in the edge shape forming step is generally about 2 nm. Therefore, the final etching damage at the end of the magnetoresistive sensor 112 can be reduced by etching this damaged layer with an Ar ion beam having a large incident angle with small etching damage. Here, the inclination angle α with respect to the substrate normal and the incidence on the substrate surface so that the outer width (INCIDENT OUTER WIDTH) and inner width (INCIDENT INNER WIDTH) of the lower layer of the magnetoresistive sensor 112 are the same as those in the edge shape forming step. Set the angles (β and γ). This removes the etching / damage layer at the end of the magnetoresistive sensor 112 and suppresses the change in the step shape between the sensor underlayer 211 and the antiferromagnetic film 212.

  Hereinafter, the junction insulating film 167 attaching step (S14) and the hard bias film 115 attaching step (S15) in this embodiment will be described in detail. FIG. 11A shows a schematic diagram of the ion beam sputtering method used in each of the above steps. In the ion beam sputtering method, the incident direction of the ion beam to the target 61 (angle between the target normal and the incident direction) and the incident direction α of the particles sputtered from the target 61 to the substrate are controlled. Then, control of the surroundings of the formed film and the end shape of the photoresist is performed. In addition, the substrate rotates uniformly during film formation.

  As a film forming method, similarly to the etching, the sputtered particles are made incident at a predetermined angle with a rotation direction angle in the substrate surface. In addition, a symmetrical angle is selected with respect to the photoresist direction with respect to the left and right and the top and bottom, and the film attachment in the vicinity of the photoresist is made symmetrical. As in the case of etching, several methods are conceivable as a method for forming a film by defining the direction of the incident particles with respect to the rotation direction of the substrate. In the film deposition process, it is preferable to adopt the same technique as that used for etching. That is, the ion beam is generated from the ion gun only when the substrate comes within the required angle range of the particle incident direction, and the film is formed by the pulsed ion beam synchronized with the rotation of the substrate.

  FIG. 11B illustrates the incident direction of sputtered particles as viewed from the substrate 51. By controlling the particle angle α incident on the substrate from the target and the angle β in the substrate rotation plane, the particle incident position can be controlled, and at the same time, the shape of the formed film in the vicinity of the photoresist can be controlled. FIG. 11B shows an example of one-time symmetrical sputter particle incidence.

  FIG. 12A schematically shows the state of the junction insulating film 167 attaching step. FIG. 12B shows the incident direction of the sputtered particles in the substrate surface, and FIG. 12C shows the acceleration voltage of the corresponding ion beam. As for the incidence of sputtered particles, the same explanation as the incidence of etching particles described with reference to FIG. What is important here is that the junction insulating film 16 is attached in accordance with the two-step step shape of the sensor underlayer 211 and the antiferromagnetic film 212. Thereby, the upper surface of the junction insulating film 16 is planarized.

  Specifically, the outer width (INCIDENT OUTER WIDTH) and the inner width (INCIDENT INNER WIDTH) shown in FIGS. 12A and 12B are made to coincide with those values in the etching step (S13). As a result, the junction insulating film 167 having a large outer thickness can be attached so as to compensate for the step between the sensor underlayer 211 and the antiferromagnetic film 212.

  That is, the thin region of the junction insulating film 167 can be limited between the junction width and the inner width (INCIDENT INNER WIDTH), and the other regions are twice as thick as the insulating film thickness in the vicinity of the junction. Can be configured. Since the area of the thin insulating film near the junction can be minimized, the withstand voltage reliability can be improved. This means that the film thickness of the insulating film near the junction can be further reduced.

  FIG. 13A shows an example of the relationship between the etching depth ratio of the sensor underlayer 211 and the antiferromagnetic film 212 by the etching and the distance from the side end of the magnetoresistive sensor 112. On the other hand, FIG. 13B shows an example of the relationship between the film thickness ratio of the junction insulating film 167 due to the adhesion and the distance from the side end of the magnetoresistive sensor 112. As can be seen from FIGS. 13A and 13B, the etching depth ratio and the film thickness ratio coincide with the distance from the side end of the magnetoresistive sensor 112. In this way, by controlling the film thickness with respect to the etching shape, the upper surface of the junction insulating film 167 can be planarized. Therefore, the hard bias underlayer film and the hard bias film, which are the next steps, can be formed with high accuracy on the planarized insulating film.

  FIG. 14 shows how the incident direction of sputtered particles is controlled when the junction insulating film 167, the hard bias underlayer film 116, and the hard bias film 115 are attached. The meaning of each figure is the same as in FIG. As described above, the junction insulating film 167 is attached by the incident of sputtered particles having a one-time symmetry.

  The hard bias base film 116 adheres to the substrate with a smaller tilt angle α than that of the junction insulating film 167, and the sputtered particles are incident from all directions. The hard bias underlayer film controls the crystal state of the hard bias film, is thin, and has a thickness of about 2.5 to 5 nm. At this time, the condition that the substrate is not attached to the side wall is selected as long as the inclination angle α of the substrate can be selected to be small. The underlying film adhering to the side wall near the junction disturbs the crystallinity of the hard bias film near the junction and degrades the magnetic characteristics at the end of the hard bias film. As a result, the magnetic field applied from the hard bias film to the free layer is disturbed, leading to deterioration of the reproduction sensor characteristics.

  After the hard bias base film 116 is formed, the hard bias film 115 is attached by one-time symmetrical sputter particle incidence. In the adhesion of the hard bias film 115, the incident angle α of the sputtered particles in the normal direction of the substrate and the angle range in the substrate surface are selected according to the film shape. By this adhesion method, magnetic anisotropy in the track width direction can be imparted to the hard bias film 115. That is, by adding magnetic anisotropy in the track width direction, the magnetostatic characteristics in the track width direction can be improved, and the characteristics of the hard bias film can be improved.

  Further, by selecting the step of attaching the hard bias film 115 by the one-time symmetric sputter particle incidence, the tip has a flat structure as shown in FIG. 13B, similar to the junction insulating film 167. It becomes possible to form a hard bias film having an increased shape. The hard bias film 115 and the underlying film 116 are formed on the planarized junction insulating film 167, and further, the sputtered particle incident angle α in the substrate normal direction and the angle range in the substrate plane are optimally selected. 13 (b). As a result, as shown in FIG. 2, the upper surface in the vicinity of the junction of the hard bias film can be formed at the same height as the upper surface of the sensor cap film 216. As a result, the lower surface in the vicinity of the junction of the upper shield film 113 can be flattened by the length of Usw. As a result, the reading error rate of adjacent data during magnetic recording data reproduction can be reduced.

  Further, the junction tip of the hard bias film 115 is thinned by one-time symmetric sputter particle incidence, but it is thick outside the sputter particle incidence outer width (INCIDENT OUTER WIDTH). Therefore, the magnetization at the junction tip is subsidized by the magnetization of the thick outer hard bias film and does not become unstable. Accordingly, it is possible to make the film thickness at the junction tip portion thinner than in the prior art, and it is possible to construct a reproducing read head having a narrower Gs than in the prior art.

  Depending on the design, two-fold symmetric sputter particle incidence may be selected for sputter particle adhesion. As described above, in the attachment of the junction insulating film 167 and the hard bias film 115, by selecting the incident direction of the sputtered particles, the shape thereof can be controlled according to the design.

  In the following, a description will be given with reference to measurement data in accordance with a comparison result between an etching and deposition method according to the present invention and a conventional method. FIG. 15A shows the relationship between the etching depth and the shunt defect rate in the etching method of the present invention and the conventional etching method. The etching depth is based on the nonmagnetic intermediate layer 214. Increasing the etching depth increases the shunt defect rate, but it has become clear that the etching method of the present invention can keep the shunt defect rate low even when the etching depth is increased.

  FIG. 15B shows the relationship between the Ar ion beam acceleration voltage and the shunt defect rate in the etching method of the present invention and the conventional etching method. Increasing the acceleration voltage of the Ar ion beam increases the shunt failure rate, but it has become clear that the shunt failure rate can be reduced even when the acceleration voltage of the Ar ion beam is set to about 200V. As understood from FIGS. 15A and 15B, it was shown that the shunt defect rate can be greatly reduced by combining these conditions and using the etching method of the present invention.

  FIG. 16 shows an example in which the junction insulating film material is selected as alumina and the hard bias magnetic field applied to the free layer from the hard bias film is measured. In the comparison, a sample to which the ion milling of the present invention and the method for forming a hard bias film of the present invention are applied is compared with a sample to which the conventional method is applied. However, the sample hard bias film to which the conventional method is applied has a magnetization amount of 35 nm · T, and the sample hard bias film to which the present invention is applied has a magnetization amount of 25 nm · T. It is set to. It was clarified that the hard bias magnetic field equivalent to that of the conventional sample can be applied to the free layer in the sample according to the present invention even when the magnetization amount is set low.

  The thickness of the hard bias film of the sample to which the present invention is applied has been reduced to 2/3 or more than the thickness of the conventional hard bias film, and further flattening has been promoted, and the sensor element characteristics have been greatly improved. Promoting.

  As mentioned above, although this invention was demonstrated taking the preferable embodiment as an example, this invention is not limited to said embodiment. A person skilled in the art can easily change, add, and convert each element of the above-described embodiment within the scope of the present invention. For example, the stacking order of the layers of the magnetoresistive sensor can be reversed. The present invention is particularly useful for a reproducing head of a magnetic disk device, but the present invention can also be applied to other magnetic detection elements.

It is sectional drawing which shows typically the structure of the magnetic head which concerns on this embodiment. It is sectional drawing which shows typically the structure of the reproducing head which concerns on this embodiment. 3 is a flowchart showing a manufacturing process of the reproducing head according to the embodiment. It is a figure which shows typically the method of etching in the manufacturing process of the reproducing head concerning this embodiment. It is a figure which shows typically the incident direction of Ar ion beam, and the mode of the etching in the etching process which concerns on this embodiment. In the etching process which concerns on this embodiment, it is a figure which shows an example of the waveform of the acceleration voltage of Ar ion beam. It is a figure which shows typically the incident direction of Ar ion beam, and the mode of the etching in the etching process which concerns on this embodiment. In the etching process which concerns on this embodiment, it is a figure which shows the change of the etching state by the incident angle of Ar ion beam. 5 is a graph showing an example of a relationship between an etching rate and an incident angle of an Ar ion beam in an etching process according to the present embodiment. It is a figure which shows typically the mode of the incident direction change of Ar ion beam in the etching process which concerns on this embodiment. It is a figure which shows typically the method of spatter adhesion in the manufacturing process of the reproducing head concerning this embodiment. In the insulating film formation process which concerns on this embodiment, it is a figure which shows typically the incident direction of a sputtered particle, and the state of the insulating film formed. 6 is a graph showing a relationship between an etching depth in etching of a magnetoresistive sensor and a film thickness in forming an insulating film in the manufacturing process of the reproducing head according to the embodiment. It is a figure which shows typically the mode of the incident direction change of the sputtered particle in the insulating film and hard bias film formation process concerning this embodiment. 4 is a graph showing a relationship between an etching depth and a shunt failure rate and a graph showing a relationship between an Ar ion beam acceleration voltage and a shunt failure rate in the etching method of the present invention and a conventional etching method. It is a graph. It is sectional drawing which shows typically the mode of the etching damage in the structure of the CPP type reproducing head concerning a prior art, and the manufacturing process of a CPP type reproducing head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic head, 2 Slider, 3 Magnetic disk, 11 Playback head 12 Recording head, 16 Junction insulating film, 111 Lower shield 112 Magnetoresistive sensor, 113 Upper shield, 115 Hard bias film 116 Hard bias base film, 117 Hard bias protective film 121 thin film coil, 122 recording magnetic pole, 123 insulator, 211 sensor underlayer 212 antiferromagnetic film, 213 fixed layer, 214 nonmagnetic intermediate layer, 215 free layer 216 sensor cap film

Claims (10)

A magnetoresistive sensor multilayer film comprising: a fixed layer having a fixed magnetization direction; a free layer whose magnetization direction is changed by an external magnetic field; and a nonmagnetic intermediate layer between the fixed layer and the free layer. A magnetic sensing element in which current flows in a direction perpendicular to the film surface of the resistance sensor multilayer film,
An upper shield electrode and a lower shield electrode formed so as to sandwich the magnetoresistive sensor multilayer film in the vertical direction;
A magnetic domain control film that is formed on both sides of the magnetoresistive sensor multilayer film and applies a bias magnetic field to the free layer;
A sensor multilayer lower layer formed below the pinned layer, the free layer, and the nonmagnetic intermediate layer, and having a step that decreases in thickness as it moves away from the magnetoresistive sensor multilayer; and
An insulating film having a step formed in contact with both end portions of the magnetoresistive sensor multilayer film, wherein the thickness on the magnetoresistive sensor multilayer film side is reduced according to the step of the lower layer;
A magnetic sensing element. The pinned layer, the free layer and the nonmagnetic intermediate layer have an end angle of 45 ° or more;
The magnetic detection element according to claim 1. In the region overlapping the magnetoresistive sensor multilayer film, the upper shield electrode is substantially flat;
The width of the substantially flat region is equal to or greater than the sum of the track width of the free layer and a value twice the interval between the upper shield electrode and the lower shield electrode.
The magnetic detection element according to claim 1. The fixed layer, the nonmagnetic intermediate layer, and the free layer are sequentially stacked from the bottom to the top,
The magnetic domain control film has a step formed with a thin thickness on the magnetoresistive sensor multilayer film side,
Near the side edge of the magnetoresistive sensor multilayer film, the height position of the upper end surface of the magnetic domain control film is 5 nm or less from the height of the upper end face of the magnetoresistive sensor multilayer film.
The magnetic detection element according to claim 1. The magnetic domain control film has a step formed with a thin thickness on the magnetoresistive sensor multilayer film side,
In the step of the magnetic domain control film, the thickness on the magnetoresistive sensor multilayer film side is ½ of the thickness on the antimagnetic resistance sensor multilayer film side.
The magnetic detection element according to claim 1. A magnetoresistive sensor multilayer film comprising: a fixed layer having a fixed magnetization direction; a free layer whose magnetization direction is changed by an external magnetic field; and a nonmagnetic intermediate layer between the fixed layer and the free layer. A method of manufacturing a magnetic sensing element in which a current flows in a direction perpendicular to a film surface of a resistance sensor multilayer film,
A multilayer film is formed on the substrate,
Adhering a patterned photoresist on the multilayer film;
In the state where the photoresist is attached, etching is performed by injecting etching particles into the multilayer film at an angle inclined with respect to the substrate to form a side end shape of the magnetoresistive sensor multilayer film,
In the etching, the etching particles are incident on the multilayer film while changing an incident angle in a limited incident angle range set in advance with respect to the photoresist.
A method of manufacturing a magnetic sensing element. In the etching, the etching particles are incident on the multilayer film at a timing corresponding to the preset limited incident angle range while rotating the substrate on the tilt angle.
A method for manufacturing the magnetic detection element according to claim 6. After forming the side end shape of the magnetoresistive sensor multilayer film, an insulating film on the side end side of the magnetoresistive sensor multilayer film and a magnetic domain control film on the side of the magnetoresistive sensor multilayer film of the insulating film are formed. And
Each of the formation of the insulating film and the magnetic domain control film is such that the material particles are incident on the substrate at an inclined angle, and the incident angle is set in a limited incident angle range set in advance with respect to the photoresist. Injecting the material particles while changing,
A method for manufacturing the magnetic detection element according to claim 6. Each of the formation of the insulating film and the magnetic domain control film causes the material particles to be incident on the substrate at a timing corresponding to the preset limited incident angle range while rotating the substrate on the tilt angle. ,
A method for manufacturing the magnetic detection element according to claim 8. The tilt angle and the incident angle range in the formation of the insulating film are set so that the upper surface of the insulating film is flattened based on the tilt angle and the incident angle range in the etching.
A method for manufacturing the magnetic detection element according to claim 8.

Images